Compositions of Group II and/or Group III base oils and alkylated fused and/or polyfused aromatic compounds

ABSTRACT

Compositions including blends of Group II and/or Group III base oils and alkylated fused and/or polyfused aromatic compositions, such as alkylated naphthalenes are provided. The use of such compositions, which exhibit excellent additive solvency, thermo-oxidative stability, hydrolytic stability, and seal swell characteristics, as lubricants is disclosed.

TECHNICAL FIELD

[0001] Compositions including blends of Group II and/or Group III baseoils and alkylated aromatic compositions, such as alkylated naphthalenesare provided. The use of such blends, which exhibit excellent additivesolvency, thermo-oxidative stability, hydrolytic stability, and sealswell characteristics, as lubricants is disclosed.

BACKGROUND

[0002] Lubricating oils are critical to the operation of the machineryof the world today.

[0003] Desirable characteristics of lubricating oils include theirability to maintain thermal and hydrolytic stability, while exhibitingswelling to seals (hereinafter “seal swell”) to ensure properfunctioning of the seals and to prevent loss of fluid and/or hardeningof the seals as well as premature decomposition of the seals.

[0004] The use of lubricating oils in combination with various additivessuch as antioxidants, and wear agents, and corrosion inhibitors toprovide a fluid that will meet the particular industrial oil applicationis known. However, in certain circumstances, the minimum performancerequirements of an industrial application cannot be met by a fluidformulated from a mineral oil and commercially available additives. Insuch circumstances, poly-alpha-olefin (hereinafter “PAO”) andcombinations of the PAOs and esters have been used as a syntheticsubstitute by those of skill in the art. See for example U.S. Pat. Nos.4,992,183; 5,519,932; 5,648,108; and 5,571,445. However, fluidsformulated from esters and PAOs exhibit decreased thermo-oxidative andhydrolytic stability.

[0005] More recently, oil refiners have discovered that the addition ofprocess steps, such as severe hydrotreatment, to remove any unsaturationand impurities from the oils, results in a product with improved thermaland thermo-oxidative stability compared to traditional solvent refinedoils. See for example U.S. Pat. Nos. 5,935,417 and 5,993,644. Suchproducts are referred to by those of skill in the art as Group II orGroup III base oils. Table 1 below describes these base oil categoriesas set forth by the American Petroleum Institute's (hereinafter “API”)definition for base oils. TABLE 1 Base Oil Viscosity Category SulfurSaturates (%) Index Group I  >0.03 and/or  <90 80 to 120 Group II ≦0.03and  ≧90 80 to 90  Group III ≦0.03 and ≧90 ≧120 Group IV All Polyalphaolefins (POA's) Group V All others not included in Groups I, II, III, orIV

[0006] Group II and Group III base oils, structurally different thanPAO's, provide exceptional thermo-oxidative stability compared totraditional mineral base oil stocks and are more economical than PAOs.However, commonly used lubricant additives, such as amine antioxidants,phenolic antioxidants, antiwear additives, and corrosion inhibitors areless soluble in these highly saturated non-polar hydrocarbon Group IIand Group III base oils. Consequently, the effectiveness of thesecommonly used lubricant additives is significantly reduced in Group IIand Group III base oils compared to traditional mineral oils. Inaddition, Group II and Group III base oils lack the ability to provideswell to certain types of seals, since the refining process removesand/or destroys the naturally occurring polar compounds found intraditional solvent refined base oils that provide seal swell andcompatibility. It is known in the art that these problems can beaddressed by blending esters with base oils, because esters have goodthermal stability as well as offer improvements both to additivesolubility and seal swell characteristics. However, the addition ofesters creates unacceptable hydrolytic instability in base oil/esterblends. The hydrolysis of esters to carboxylic acid in the presence oftrace amounts of moisture leads to an unacceptable acceleration of baseoil oxidation when used under normal conditions.

[0007] Therefore, it would be advantageous to provide a compositionincluding Group II and/or Group III base oils which exhibits additivesolvency, suitable seal swell, thermo-oxidative stability, andhydrolytic stability.

[0008] U.S. Pat. No. 5,602,086 discloses the inclusion of alkylatednaphthalene blending stocks with PAO based fluids to provide desirablephysical properties. It does not disclose or suggest the blending ofalkylated naphthalenes with materials other than PAO, let alone thatdesirable physical properties could be achieved from such a blend.

[0009] Therefore, it would be unexpected that a composition includingGroup II and/or Group III base oils would exhibit additive solvency,suitable seal swell, thermo-oxidative stability, and hydrolyticstability.

SUMMARY

[0010] It has now surprisingly been found that compositions includingGroup II and/or Group III base oils blended with alkylated fused and/orpolyfused aromatic compounds exhibit additive solvency and superiorthermal and hydrolytic stability compared to base oils either alone orblended with esters, while maintaining seal swell characteristicssimilar to blends of base oils and esters.

[0011] In one embodiment, the composition includes between about 51weight percent to about 99 weight percent of the composition Group IIand/or Group III base oil and between 1 weight percent to about 49weight percent of the composition includes alkylated fused and/orpolyfused aromatic compounds.

[0012] In another embodiment, suitable alkylated fused and/or polyfusedaromatic compounds include, but are not limited to, anthracene,phenanthrene, pyrene, indene, benzanthrene, chrysene, tripbenylene, andnaphthalene. In particularly useful embodiments, the alkylatednaphthalenes include at least one C₆ to C₃₀. alkyl chain.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0013] It has been found that mineral base oils can advantageously becombined with alkylated fused and/or polyfused aromatic compounds toform compositions useful as lubricants having additive solvency andsuperior thermal and hydrolytic stability compared to base oils eitheralone or blended with esters, while maintaining seal swellcharacteristics similar to blends of base oils and esters.

[0014] The composition which includes blends of mineral base oils andalkylated fused and/or polyfused aromatic compounds can be preparedusing conventional techniques. For example, Group II and/or Group IIIbase oils and alkylated naphthalenes can be added to a reaction vesseland mixed at temperatures from about 40° C. to about 60° C. for a periodof time ranging from about 20 minutes to about 2 hours. Suitablecompositions have a kinematic viscosity of from about 20 to about 80 cStand more preferrably from about 44 to about 56 cSt as measured at 40° C.in accordance with ASTM test D445.

[0015] In one embodiment, the mineral base oils comprise between 51weight percent to about 99 weight percent of the composition, with fromabout 60 weight percent to about 95 weight percent of the compositionbeing preferred, and from about 80 weight percent to about 90 weightpercent of the composition being most preferred. The alkylated fusedand/or polyfused aromatic compounds comprise from about 1 weight percentto about 49 weight percent of the composition, and preferably from about5 weight percent to about 40 weight percent of the composition, withfrom about 10 weight percent to about 20 weight percent of thecomposition being most preferred.

[0016] Optionally, the composition may include up to about 5 weightpercent of an additive package. Suitable additive packages may containother performance enhancing additives known in the art which include,but are not limited to, antioxidants, dispersants, antiwear additives,extreme pressure additives, rust and corrosion inhibitors, copper metalpassivators, viscosity index improvers, friction modifiers and the like.

[0017] Suitable mineral base oils include Group II and/or Group III baseoils and are a complex mixture of hundreds of isomers of differentcarbon number (generally n-parraffins, cycloparaffins, and naphthenics)and contain some small amount of unsaturation (generally less than 10%)as well as other trace impurities such as sulfur and nitrogen. Asmentioned hereinabove, Group II and Group III base oils may be preparedin accordance with the teachings of U.S. Pat. Nos. 5,935,417 and5,993,644, the contents of both of which are incorporated herein byreference. Typically, processes commonly used to produce conventionalmineral oil base stocks known in the art are first applied to the crudeoil. For example, the crude oil may be subjected to distillation,solvent dewaxing, and solvent extraction of aromatic compounds. Toproduce Group II and Group III base oils, the oil is then subjected tofurther apart processing referred to in the art as hydrotreating,hydrocracking, hydroisomerization and hydrofining. In such a process,the oil is mixed with hydrogen in a reactor in the presence of acatalyst to hydrogenate most of the double

[0018] bonds or unsaturated hydrocarbons. Depending on the severity ofthe hydrotreatment, aromatic molecules still remaining afterconventional solvent extraction are also hydrogenated to saturated ringstructures. In addition, the saturated ring structures can also be ringopened to linear molecules. Most of the sulfur and nitrogen impuritiesare converted to hydrogen sulfide and ammonia which are removed. In someinstances, the feed for this hydrotreating process is not a conventionalbase oil at all, but the waste products isolated during solventdewaxing. The result is a base oil which has more n-parafins andisoparaffins than traditional base oils, low unsaturation (generallyless than 2%), very low levels of sulfur and nitrogen impurities, and ahigh viscosity index. Group III base oils are subjected to a more severehydrotreating process than Group II base oils.

[0019] Suitable fused and/or polyfused aromatic compounds include, butare not limited to, anthracene, phenanthrene, pyrene, indene,acenaphthylene, benzanthrene, chrysene, triphenylene, and naphthalene,with naphthalene being preferred.

[0020] Suitable alkylated naphthalenes include these of the formula:

[0021] wherein R and R′ are linear or branched alkyl groups of typicallyabout C₆ to C₃₀ alkyl, such as those derived from a C₆ to C₃₀ alphaolefin alkylating agent, and m and n are independently integers from 0-4where the sum of m+n≧1. Preferred alkylated naphthalenes are about C₆ toC₁₆ linear or branched alkyl groups. More preferably the alkyl chain isderived from a C₈ to C₁₂ alpha olefin alkylating agent. In general, thepreferred number of alkyl groups on the naphthalene ring will decreaseas the length of the alkyl group increases. The alkylated naphthalenemay also be a mixture of various mono, di, and higher order alkylatednaphthalenes. Suitable alkylating agents include 1-octene, 1-decene,1-dodecene, 1-tetradecene, 1-hexadecene, an isomeric mixture of branchedC₆ to C₃₀ olefins, nonene, and tetrapropylene.

[0022] The alkylated naphthalenes can be prepared by any means known inthe art. Suitable methods involve the alkylation of naphthalene with anolefin, alcohol, alkylhalide, or other alkylating agents known to thoseof skill in the art in the presence of a catalyst. Suitable catalystsinclude any of Lewis acid or super acid catalysts known in the art.

[0023] Suitable Lewis acids include boron trifluoride, iron trichloride,tin tetrachloride, zinc dichloride, and antimony pentafluoride. Acidicclays, silica, or alumina are suitable. See for example U.S. Pat. Nos.4,604,491 and 4,714,794. Suitable super acid catalysts includetrifluoromethane sulfonic acid, hydrofluoric acid ortrifluoromethylbenzene sulfonic acid. Other suitable catalysts includeacidic zeolite catalysts, such as Zeolite Beta, Zeolite Y, ZSM-5,ZSM-35, and USY. In one embodiment, it is preferred to alkylatenaphthalene with an olefin using aluminum chloride as the catalyst. Theuse of a co-catalyst such as nitromethane or nitrobenzene to promote thereaction is also suitable. See for example U.S. Pat. No. 2,764,548 toKing et al. In another embodiment, it is preferred to alkylatenaphthalene with an olefin using trifluoromethane sulfonic acid as thecatalyst.

[0024] In another embodiment, compounds other than naphthalene may bealkylated to provide suitable alkylated naphthalenes. In particular, theaddition of longer chain alkyl groups, e.g. about C₆ to about C₃₀, toshort chain alkylated naphthalenes, e.g. methyl naphthalene, ethylnaphthalene, propyl naphthalene, butyl naphthalene, etc. is suitable.

[0025] In order that those skilled in the art may be better able topractice the compositions and methods described herein, the followingexamples are given as an illustration of the blends herein. It should benoted that the invention is not limited to the specific details embodiedin the examples. In addition, all percentages are weight percentagesbased on the total weight of the composition unless otherwise indicated.

EXAMPLES Example 1

[0026] 20% Blend of Alkylated Naphthalene in Group III Base Oil

[0027] Alkylated naphthalene I (360 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KR-012 andhaving the physical properties listed in Table 2 hereinbelow, and 1435grams of a 7 cSt (centistoke) Group III base oil (commercially availablefrom Chevron Chemical Company, Richmond, Calif., under the tradenameUCBO 7R) were added to a reaction vessel along with 3.6 grams ofNA-LUBE® AO-140 (an amine antioxidant commercially available from KingIndustries, Norwalk Conn.) and 1.8 grams of NA-LUBE® AO-240 (a phenolic

[0028] antioxidant commercially available from King Industries, NorwalkConn.). The contents of the reaction vessel were stirred at 60° C. for20 minutes.

Example 2

[0029] 20% Blend of Alkylated Naphthalene in Group III Base OilAlkylated naphthalene 2 (360 grams), commercially from King Industries,Norwalk Conn., under the tradename NA-LUBE® KX-1070 and exhibiting thephysical properties listed in Table 2 hereinbelow, and 3.6 grams of a 7cSt Group III base oil (commercially available from Chevron ChemicalCompany, Richmond, Calif. under the tradename UCBO 7R) were added to areaction vessel along with 3.6 grams of NA-LUBE® AO-140 (an amineantioxidant commercially available from King Industries, Norwalk Conn.)and 1.8 grams of NA-LUBE® AO-240 (a phenolic antioxidant, commerciallyavailable from King Industries, Norwalk Conn.). The contents of thereaction vessel were stirred at 60° C. for 20 minutes.

Example 3

[0030] Preparation of Alkylated Naphthalene 3

[0031] An alkylnaphthalene fluid, exhibiting the properties listed inTable 2 hereinbelow, was prepared by reacting 1.4 moles oftetrapropylene with 1 mole of naphthalene in the presence of 5 mole %aluminum chloride catalyst.

[0032] The reaction was quenched with an amount of water sufficient toinactivate the catalyst and the organic phase was isolated. Theunreacted naphthalene and olefin were removed using known distillationtechniques. The treatment to remove residual reactants occurred at 200°C. for 2 hours.

Example 4

[0033] 20% Blend of Alkylated Naphthalene 3 in 7 cSt Group III Oil

[0034] The alkylated naphthalene of Example 3 (360 grams) and 1435 gramsof a Group III base oil (commercially available from Chevron ChemicalCompany, Richmond, Calif. under the tradename UCBO 7R) were added to areaction vessel along with 3.6 grams of NA-LUBE® AO-140 (an amineantioxidant commercially available from King Industries, Norwalk Conn.)and 1.8 grams of NA-LUBE® AO-240 (a phenolic antioxidant commerciallyavailable from King Industries, Norwalk Conn.). The contents of thereaction vessel were stirred at 60° C. for 20 minutes.

Comparative Example 1

[0035] 360 grams of a synthetic diester having a kinematic viscosity at40° C. of 26.8 cSt (commercially available from Henkel, under the nameEmery 2971) and 1435 grams of a 7 cSt Group III base oil (commerciallyavailable from Chevron Chemical Company, Richmond, Calif. under thetradename UCBO 7R) were added to a reaction vessel along with 3.6 gramsof NA-LUBE® AO-140 (an amine antioxidant commercially available fromKing Industries, Norwalk Conn.) and 1.8 grams of NA-LUBE®AO-240 (aphenolic antioxidant commercially available from King Industries,Norwalk Conn.). The contents of the reaction vessel were stirred at 60°C. for 20 minutes.

Comparative Example 2

[0036] 360 grams of a synthetic polyol ester based on trimethylolpropane (TMP) having a kinematic viscosity at 40° C. of 19.5 cSt(commercially available from Henkel Corporation, under the name Emery2925) and 1435 grams of a 7 cSt Group III base oil (commerciallyavailable from Chevron Chemical Company, Richmond, Calif. under thetradename UCBO 7R) were added to a reaction vessel along with 3.6 gramsof NA-LUBE® AO-140 (an amine antioxidant commercially available fromKing Industries, Norwalk Conn.) and 1.8 grams of NA-LUBE® AO-240 (aphenolic antioxidant commercially available from King Industries,Norwalk Conn.). The contents of the reaction vessel were stirred at 60°C. for 20 minutes.

Comparative Example 3

[0037] 1794.6 grams of a Group III base oil (commercially available fromChevron Chemical Company, Richmond, Calif. under the tradename UCBO 7R)were added to a reaction vessel along with 3.6 grams of NA-LUBE® AO-140(an amine antioxidant commercially available from King Industries,Norwalk Conn.) and 1.8 grams of NA-LUBE® AO-240 (a phenolic antioxidantcommercially available from King Industries, Norwalk Conn.). Thecontents of the reaction vessel were stirred at 60° C. for 20 minutes.

[0038] The physical properties of the alkylated naphthalenes of Examples1-3 are shown in Table 2 below. TABLE 2 Physical Properties of AlkylatedNaphthalenes Alkylated Naphthalene 1 2 3 Kinematic Viscosity @  100 cSt1100 cSt 3650 cSt 40° C. (ASTM D445) Kinematic Viscosity @ 11.1 cSt 22.3 cSt  42.9 cSt 100° C. (ASTM D445) Viscosity Index 97 — — PourPoint (ASTM D97) −23° C.  3° C. Greater than 10 Aniline Point  55° C.42° C. — (ASTM D611)

[0039] TABLE 3 Compositions of Examples Comparative ComparativeComparative Example 1 2 4 1 2 3 7 cSt Group 79.7% 79.7% 79.7% 79.7%79.7% 79.7% III Base Oil Alkylated   20% Naphthalene 1 Alkylated   20%Naphthalene 2 Alkylated   20% Naphthalene 3 Synthetic   20% DiesterSynthetic   20% Polyol Ester Amine  0.2%  0.2%  0.2%  0.2%  0.2%  0.2%Antioxidant (NA LUBE ® AO-140) Phenolic  0.1%  0.1%  0.1%  0.1%  0.1% 0.1% Antioxidant (NA LUBE ® AO-240) Kinematic 44.9 51.2 56 38.1 34.432.3 Viscosity @ 40° C. - (ASTM D445) Kinematic 7.4 7.6 8 6.8 6.3 6.1Viscosity @ 100° C. - (ASTM D445) Viscosity 130 112 110 137 137 138Index Pour Point, −21 −24 −21 −18 −21 −18 ° C. (ASTM D-97)

[0040] The thermal stability of the compositions of Examples 1, 2, and 4and Comparative Examples 1-3 were evaluated using Federal Test Method3411. In this test, the oils were heated at 274° C. for 96 hours in asealed tube in the absence of moisture and air, but in the presence of asteel coupon. The changes in viscosity, acid number, and discolorationand corrosion of the steel coupon are all indicative of oildecomposition. The results of the tests are reported in Table 4 below.They show that there are no adverse effects incurred by the inclusion ofalkylated naphthalenes in the Group III base oil formulation.Conversely, incorporation of synthetic esters leads to undesirablelosses in viscosity, increase in acid number, and discoloration of thesteel coupon. TABLE 4 FTM-3411 Thermal Stability Comparative ComparativeComparative Example 1 2 4 1 2 3 Change in −0.80% 1.42% 0.65% −15.78%−10.02% −0.86% Viscosity Change in −0.03% −0.02 −0.02 0.52 5.97 0.03Acid Number Change in −0.008 0.008 −0.017 0.050 −2.970 0.000 MetalWeight, mg/cm² Appearance Shiny Shiny Shiny Blue-Black Shiny EtchedGold-Shiny Oil Light Amber Medium Medium Very Dark Black CleanAppearance Amber Amber Amber Test Cell Clean Clean Clean Clean HeavyBlack Clean Appearance Stains Sediment Trace Light Very Light LightSediment Clean

[0041] The seal swelling characteristics of compositions of Examples 1,2, and 4 Comparative Examples 1-3 on two materials commonly used inseals were evaluated by the ASTM D 417 and ASTM D 2240 methods, SealSwell and Percent Hardness Change, respectively.

[0042] Coupons of the “seal” materials tested, i.e. nitrile rubber (NBR)commercially available from Test Engineering, Cimerron Path, SanAntonio, Tex. and Fluoroelastomer (also commercially available from TestEngineering, Cimerron Path, San Antonio, Tex., as Viton F975) wereimmersed in the compositions of Examples 1, 2, 4, and ComparativeExamples 1-3 for 70 hours, at 100° C. for the NBR seal and at 150° C.for the Viton F975, respectively. The volume and hardness of the samplecoupons were measured before and after the test and the percent changerecorded. Specifications for the desired degree of seal swell depend onthe particular application, but typical values are in the range of 3-15%for NBR and very little or no change for Fluoroelastomer. Anysignificant change in the hardness (negative or positive) is considereddetrimental to the function and service

[0043] life of the seal. The results reported in Table 5 illustrate thatboth NBR and Fluoroelastomer seals exposed to the compositions ofExamples 1, 2 and 4, i.e. the compositions containing blends ofalkylated naphthalenes and base oils, exhibited a desirable degree ofswell compared to the base oils alone (which exhibit little or noswell). Moreover, both NBR and Fluoroelastomer seals exposed to thecompositions of Examples 1, 2, and 4 exhibit seal swell comparable toNBR and Fluoroelastomer seals exposed to the compositions of ComparativeExamples 1-2, i.e. blends of base oils and synthetic esters. TABLE 5Seal Swell and Percent Hardness Comparative Comparative ComparativeExample 1 2 4 1 2 3 70 hrs @ 100° C., Nitrile Buna-N ASTM D- 5.71% 9.92%8.92% 11.08% 12.53% 2.33% 417 Swell ASTM D- −2 −5 −5 −10 −10 0 2240 %Hardness 70 hrs @ 150° C., Fluoro- elastomer, F975, (MT-1 Spec) ASTM D-0.23% 0.31% 0.31% 0.83% 1.05% 0.11% 417 Swell ASTM D- −1 −1 −1 0 0 12240 % Hardness

[0044] The hydrolytic stability of compositions of Examples 1, 2, 4 andComparative Examples 1-3 was evaluated by the ASTM D 2619 HydrolyticStability Test. 75 grams of Example 1 were placed in a sealed bottlealong with 25 grams of water in the presence of a copper strip androtated and heated at 93° C. for 48 hours. Compositions of Examples 2and 4 and Comparative Examples 1-3 were subjected to the same treatment,respectively. The acidity of the water layer of each sample was measuredto determine the degree of hydrolysis of the compositions. The weightloss and discoloration of the copper strip in each bottle was measured.The data set forth below in Table 6 indicates that the extent ofhydrolysis is minimal compared to Comparative Example 3, i.e. base oilnot blended with any modifier. The degree of hydrolysis of thecompositions of the Comparative Examples 1-2, which contain estersblended with base oils, indicates that the use of esters has adetrimental effect of the hydrolytic stability of the overallformulation compared to either unblended base oils or the compositionsof Examples 1, 2, and 4. Therefore, the compositions containing thealkylated naphthalenes as base oil modifiers are an improvement oversimilar compositions blended with synthetic esters. TABLE 6 ASTM D 2619Hydrolytic Stability Comparative Comparative Comparative Example 1 2 4 12 3 Acid Number 1.5 2.7 2 7.1 7.2 <1 Of Water Layer in mg KOH/g

[0045] As the data in Tables 4, 5, and 6 illustrate, the compositionsincluding alkylated naphthalenes and base oils exhibit seal swellcharacteristics similar to compositions containing esters and base oils,while providing superior thermal and hydrolytic stability.

Example 5

[0046] Blend of 75% of 7 cSt Group II Base Oil and 25% AlkylatedNaphthalene 1

[0047] Alkylated naphthalene 1 (25 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KR-012 and75 grams of a 7 cSt (centistoke) Group III base oil (commerciallyavailable from Chevron Chemical Company, Richmond Calif., under thetradename UCBO 7R) were added to a reaction vessel. The contents of thereaction vessel were stirred at 60° C. for 20 minutes.

Example 6

[0048] Blend of 50% Alkylated Naphthalene and 50% Group III Base Oil

[0049] Alkylated naphthalene 1 (50 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KR-012 and50 grams of a 7 cSt (centistoke) Group III base oil (commerciallyavailable from Chevron Chemical Company, Richmond Calif., under thetradename UCBO 7R) were added to a reaction vessel and stirred at 60° C.for 20 minutes.

Example 7

[0050] Blend of 75% Alkylated Naphthalene and 25% Group III Base Oil

[0051] Alkylated naphthalene 1 (75 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KR-012 and25 grams of a 7 cSt (centistoke) Group III base oil (commerciallyavailable from Chevron Chemical Company, Richmond Calif., under thetradename UCBO 7R) were added to a reaction vessel and stirred at 60° C.for 20 minutes.

Example 8

[0052] Blend of 25% Alkylated Naphthalene 2 and 75% Group III Base Oil

[0053] Alkylated naphthalene 2 (25 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KX-1070 and75 grams of a 7 cSt Group III base oil (commercially available fromChevron Chemical Company, Richmond Calif. under the tradename UCBO 7R)were added to a reaction vessel and stirred at 60° C. for 20 minutes.

Example 9

[0054] Blend of 50% Alkylated Naphthalene 2 and 50% Group III Base Oil

[0055] Alkylated naphthalene 2 (50 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KX-1070 and50 grams of a 7 cSt Group III base oil (commercially available fromChevron Chemical Company, Richmond Calif. under the tradename UCBO 7R)were added to a reaction vessel and stirred at 60° C. for 20 minutes.

Example 10

[0056] Blend of 75% Alkylated Naphthalene 2 and 25% Group III Base Oil

[0057] Alkylated naphthalene 2 (75 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KX-1070 and25 grams of a 7 cSt Group III base oil (commercially available fromChevron Chemical Company, Richmond Calif. under the tradename UCBO 7R)were added to a reaction vessel and stirred at 60° C. for 20 minutes.

Example 11

[0058] Blend of 20% Alkylated Naphthalene 1 and 80% of 7 cSt Group IIIBase Oil

[0059] Alkylated naphthalene I (2 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KR-012 and8 grams of a 7 cSt Group III base oil (commercially available fromChevron Chemical Company, Richmond Calif. under the tradename UCBO 7R)were added to a reaction vessel and stirred at 60° C. for 20 minutes.

Example 12

[0060] Blend of 20% Alkylated Naphthalene 2 and 80% Group III Base Oil

[0061] Alkylated naphthalene 2 (2 grams), commercially available fromKing Industries, Norwalk Conn., under the tradename NA-LUBE® KX-1070 and8 grams of a 7 cSt Group III base oil (commercially available fromChevron Chemical Company, Richmond Calif. under the tradename UCBO 7R)were added to a reaction vessel and stirred at 60° C. for 20 minutes.

Example 13

[0062] Blend of 20% Alkylated Naphthalene 3 and 80% Group III Base Oil

[0063] The alkylated naphthalene 3 of example 3 (2 grams) and 8 grams ofa 7 cSt Group III base oil (commercially available from Chevron ChemicalCompany, Richmond Calif. under the tradename UCBO 7R) were added to areaction vessel and stirred at 60° C. for 20 minutes.

Comparative Example 4

[0064] A 7 cSt Group III base oil (commercially available from ChevronChemical Company, Richmond, Calif., under the tradename UCBO 7R) wasused as Comparative Example 4.

Comparative Example 5

[0065] Alkylated naphthalene 1, commercially available from KingIndustries, Norwalk Conn., under the tradename NA-LUBE® KR-012 was usedas Comparative Example 5.

Comparative Example 6

[0066] Alkylated naphthalene 2, commercially available from KingIndustries, Norwalk Conn., under the tradename NA-LUBE® KX-1070 was usedas Comparative Example 6.

Comparative Example 7

[0067] A synthetic diester having a kinematic viscosity at 40° C. of26.8 cSt (available from Henkel Corporation as Emery 2925) was used asComparative Example 7.

Comparative Example 8

[0068] A synthetic polyol ester based on trimethylol propane (TMP)having a kinematic viscosity at 40° C. of 19.5 cSt (available fromHenkel Corporation as Emery 2970) was used as Comparative Example 8.

[0069] Thermo-oxidative Stability

[0070] Tables 7 and 8 below set forth the thermo-oxidative stability ofthe alkylated naphthalenes in combination with a Group III base oil atvarious concentrations as determined using the ASTM D 2272 Rotory BombOxidation (RBOT) method and Pressure Differential Scanning Calorimetry(PDSC).

[0071] The RBOT test utilizes an oxygen-pressure bomb to evaluate theoxidation stability of oils in the presence of water and a coppercatalyst coil at 150° C. The test oil, water and a copper catalyst coil,contained in a covered glass container, are placed in a bomb equippedwith a pressure gage. The bomb is charged with oxygen to a pressure of90 psi, placed in a constant temperature oil bath at 150° C., androtated axially at 100 rpm at an angle of 30° from the horizontal. Thetime period required for the pressure to drop to 25 psi is the measureof the oxidation stability of the test sample. The longer the time, thebetter the oxidative stability of the material.

[0072] The thermo-oxidative stability of various blends of alkylatednaphthalenes and Group III base oil were also evaluated by PDSC. This isa calorimetric test that measures the induction time to an exotherm orendotherm under specific conditions of temperature and atmosphere. Theexotherm or endotherm is associated with decomposition of the sample.The heat flow as a function of time is charted on a two dimensionalgraph with the “x” axis being time (minutes) and the “y” axis being heatflow (watts/g). Under conditions where no decomposition occurs ahorizontal line is plotted (ie., slope equals zero). The induction timecorresponds to the point on the graph where the slope becomes positive.

[0073] A TA Instruments Model 910 PDSC interfaced to a Series 2000Thermal Analyst computer was employed. Iso-Trak™ control mode was usedfor highest sensitivity. Samples were weighed into open aluminum pansand heated at a rate of 40° C./min. to a target temperature and thenheld isothermally until an exotherm was observed. Data was collected atboth 160° C. and 170° C. An atmosphere of 150 psi pure air was used forall tests. TABLE 7 Summary of RBOT and PDSC Oxidative Induction Timesfor Blends of Alkylated Naphthalene 1 and 7 cSt Group III Base Oil PDSCPercent RBOT (160 C. isothermal) 7 cSt Group III Percent Induction TimeInduction Time Blend Base Oil Alkylated Naphthalene 1 (Minutes)(Minutes) Comparative 100 0 18  1 Example 4 Example 5 75 25 35 22Example 6 50 50 63 82 Example 7 25 75 71 — Comparative 0 100 83 84Example 5

[0074] TABLE 8 Summary of RBOT and PDSC Oxidative Induction Times forBlends of Alkylated Naphthalene 2 and Group III Base Oil Percent PDSCPDSC 7 cSt Group Percent RBOT (160° C. isothermal) (170° C. isothermal)III Alkylated Induction Time Induction Time Induction Time Blend BaseOil Naphthalene 2 (Minutes) (Minutes) (Minutes) Comparative 100 0 18 1<1 Example 4 Example 8 75 25 62 69 20 Example 9 50 50 95 83 — Example 1025 75 138 102 91 Comparative 0 100 242 >>130 129 Example 6

[0075] The results reported in Tables 7 and 8 clearly indicate that 1)the thermo-oxidative stability of the base oil blends increases withincreasing concentration of the alkylated naphthalene and 2) that thereis an improvement in thermo-oxidative stability even at lowconcentrations of the alkylated naphthalenes.

[0076] The improvement in thermo-oxidative stability of combinations ofalkylated napthalenes with Group III base oils over combinations ofother base oil modifiers with Group III base oils is further illustratedby the data in Table 9. Blends of 20 weight % of various alkylatednaphthalenes in Group III base oil exhibit improvement in induction timeover the 7 cSt base oil alone (Comparative Example 4), and thecombination of esters with Group III base oils (Comparative Examples 7and 8). TABLE 9 Pressure Differential Scanning Calorimetry InductionTimes at 160° C. for Blends of 20 wt % of the in 7 cSt Group III OilAdditive at 20 wt % in 7 cSt Induction Time Group III Base Oil (minutes)Comparative Example 4 0 Example 11 18 Example 12 48 Example 13 >80Comparative Example 7 0 Comparative Example 8 0

[0077] It will be understood that various modifications may be made tothe embodiments disclosed herein. For example, alkylated fused and/orpolyfused aromatic compounds may possess functional groups in additionalto alkyl groups. Therefore, the above description should not beconstrued as limiting, but merely as exemplifications of preferredembodiments. Those skilled in the art will envision other modificationswithin the scope of the claims appended hereto.

What is claimed is:
 1. A composition comprising a mixture of at leastone mineral base oil and an alkylated compound selected from the groupconsisting of fused aromatic compounds and polyfused aromatic compounds.2. The composition of claim 1, wherein the alkylated compound isselected from the group consisting of anthracene, phenanthrene, pyrene,indene, acenaphthylene, benzanthrene, chysene, triphenylene.
 3. Thecomposition of claim 1, wherein the alkylated compound is alkylatednaphthalene.
 4. The composition of claim 1, further comprising anadditive package.
 5. The composition of claim 4, wherein the additivepackage comprises at least one member selected from the group consistingof antioxidants, dispersants, antiwear additives, extreme pressureadditives, rust and corrosion inhibitors, copper metal passivators,viscosity index improvers, and friction modifiers.
 6. The composition ofclaim 1, wherein the mineral base oil is selected from the groupconsisting of Group II base oils, Group III base oils, and mixturesthereof.
 7. The composition of claim 1, wherein the mineral base oil isa Group III base oil.
 8. The composition of claim 1, wherein the baseoil comprises from about 51 weight percent to about 99 weight percent ofthe composition.
 9. The composition of claim 1, wherein the base oilcomprises from about 60 weight percent to about 95 weight percent of thecomposition.
 10. The composition of claim 1, wherein the base oilcomprises from about 80 weight percent to about 90 weight percent of thecomposition.
 11. The composition of claim 1, wherein the alkylatedcompound comprises from about 1 weight percent to about 49 weightpercent of the composition.
 12. The composition of claim 1, wherein thealkylated compound comprises from about 5 weight percent to about 40weight percent of the composition.
 13. The composition of claim 1,wherein the alkylated compound comprises from about 10 weight percent toabout 20 weight percent of the composition.
 14. The composition of claim1, wherein the additive package comprises up to about 5 weight percentof the composition.
 15. The composition of claim 1, wherein thealkylated compound comprises at least one C₆ to C₃₀ alkyl chain.
 16. Thecomposition of claim 15, wherein the alkyl chain is derived from a C₆ toC₃₀ alpha olefin alkylating agent.
 17. The composition of claim 1,wherein the alkylated compound comprises at least one C₆ to C₁₆ alkylchain.
 18. The composition of claim 17, wherein the alkyl chain isderived from a C₆ to C₁₆ alpha olefin alkylating agent.
 19. Thecomposition of claim 1, wherein the alkylated compound comprises atleast one C₈ to C₁₂ alkyl chain.
 20. The composition of claim 19,wherein the alkyl chain is derived from a C₈ to C₁₂ alpha olefinalkylating agent.
 21. The composition of claim 1, wherein the alkylatedcompound comprises at least one C₈ alkyl chain.
 22. The composition ofclaim 21, wherein the alkyl chain is derived from 1-octene.
 23. Thecomposition of claim 1, wherein the alkylated compound comprises atleast one C₁₀ alkyl chain.
 24. The composition of claim 23, wherein thealkyl chain is derived from 1-decene.
 25. The composition of claim 1,wherein the alkylated compound comprises at least one C₁₂ alkyl chain.26. The composition of claim 25, wherein the alkyl chain is derived from1-dodecene.
 27. The composition of claim 15, wherein the alkyl chain isderived from an alkylating agent selected from the group consisting of1-tetradecene, 1-hexadecene, an isomeric mixture of branched C₆ to C₃₀olefins, and tetrapropylene.
 28. A composition comprising a mixture of aGroup III base oil and an alkylated naphthalene.
 29. The composition ofclaim 28, wherein the alkylated naphthalene comprises at least one C₆ toC₃₀ alkyl chain.
 30. The composition of claim 29, wherein the alkylchain is derived from a C₆ to C₃₀ alpha olefin alkylating agent.
 31. Thecomposition of claim 28, wherein the alkylated naphthalene comprises atleast one C₆ to C₁₆ alkyl chain.
 32. The composition of claim 31,wherein the alkyl chain is derived from a C₆ to C₁₆ alpha olefinalkylating agent.
 33. The composition of claim 28, wherein the alkylatednaphthalene comprises at least one C₈ to C₁₂ alkyl chain.
 34. Thecomposition of claim 33, wherein the alkyl chain is derived from a C₈ toC₁₂ alpha olefin alkylating agent.
 35. The composition of claim 28,wherein the alkylated naphthalene comprises at least one C₈ alkyl chain.36. The composition of claim 26, wherein the alkyl chain is derived from1-octene.
 37. The composition of claim 28, wherein the alkylatednaphthalene comprises at least one C₁₀ alkyl chain.
 38. The compositionof claim 37, wherein the alkyl chain is derived from 1-decene.
 39. Thecomposition of claim 32, wherein the alkylated naphthalene comprises atleast one C₁₂ alkyl chain.
 40. The composition of claim 47, wherein thealkyl chain is derived from 1-dodecene.